Method for corroboration and transferring trust between network databases for enhanced positioning accuracy

ABSTRACT

Techniques for transferring trust between networks are described herein. An example of a method of using a mobile device to transfer trust between networks described herein includes receiving WAN base station information including a WAN base station trustworthiness value, determining a WAN position estimate for the mobile device based on the WAN base station information, receiving access point information including an access point trustworthiness value, determining an access point position estimate for the mobile device based on the access point information, determining if the WAN position estimate and the access point position estimate are corroborated, and increasing the access point trustworthiness value if the WAN position estimate and the access point position estimate are corroborated and the WAN base station trustworthiness value is higher than the access point trustworthiness value.

CROSS-REFERENCE TO RELATED ACTIONS

This application claims the benefit of U.S. Provisional Application No.61/727,243, entitled “METHOD FOR CORROBORATION AND TRANSFERRING TRUSTBETWEEN WIFI AND CELL NETWORK DATABASES FOR ENHANCED POSITIONINGACCURACY,” filed on Nov. 16, 2012, which is assigned to the assigneehereof, and expressly incorporated herein by reference.

BACKGROUND

1. Field

This disclosure relates in general to radio location systems and, morespecifically, but not by way of limitation, to transferring locationrelated trust information between Access Point and Wide Area Networks.

2. Information

There is an ever growing desire to know the geographic position ofvarious mobile devices. For example, some cellular phone operators mayneed to comply with requirements to locate handsets for emergencypurposes. Once position is known, emergency personnel can be dispatchedto aid resolving the emergency. Knowing geographic location serves manyother purposes such as location-based advertising, child supervision,automated parolee supervision, reverse 911, fleet vehicle tracking, etc.

Currently, there are many ways to estimate a position of a mobile deviceon a network. For example, Global Navigation Satellite System (GNSS)solutions on a mobile device may provide position estimates that aremost accurate when the mobile device is located in outdoor and openspace environments. In another example, Wide Area Networks (WAN) basestations and Access Point (AP) networks (e.g., using WiFi, CDMA, WCDMA,LTE or other WAN Femtocells, or Bluetooth) can be used to estimate theposition of a mobile device.

In general, AP based positioning is dependent on the integrity ofinformation stored in an Almanac. In an embodiment, an almanac can be adatabase including a Service Set Identification (SSID), Media AccessControl (MAC), or other appropriate address identifier, and positioninformation associated with a wireless access point. The term accesspoint can be a short range wire transceiver including WiFi access pints,Bluetooth transceivers, femtocells, and other short range wirelesstransceivers. The integrity of an almanac can be degraded due to theease with which an owner of a wireless access point can move thehardware between locations without registering a new location for theAP. The integrity of the almanac may also be diminished by incorrectsignal measurement, corrupt data, and other system failures.

In some areas of the world a stable AP almanac can be established, butthe integrity of the location information in a WAN almanac may belacking. In this case, access point generated position estimates can beused to verify the WAN base station positions.

SUMMARY

An example of a method of using a mobile device to transfer trustbetween networks according to the disclosure includes receiving WAN basestation information including a WAN base station trustworthiness value,determining a WAN position estimate for the mobile device based on theWAN base station information, receiving access point informationincluding an access point trustworthiness value, determining an accesspoint position estimate for the mobile device based on the access pointinformation, determining if the WAN position estimate and the accesspoint position estimate are corroborated, and increasing the accesspoint trustworthiness value if the WAN position estimate and the accesspoint position estimate are corroborated and the WAN base stationtrustworthiness value is higher than the access point trustworthinessvalue.

Implementations of the method may include one or more of the followingfeatures. Increasing the WAN base station trustworthiness value if theWAN position estimate and the access point position estimate arecorroborated and the access point trustworthiness value is higher thanthe WAN base station trustworthiness value. Determining a combinedposition estimate based on the WAN base station information and theaccess point information, and outputting the combined position estimate.Disregarding the access point position estimate if the WAN positionestimate and the access point position estimate are uncorroborated andthe WAN base station trustworthiness value is higher than the accesspoint trustworthiness value, outputting the WAN position estimate anddecreasing the access point trustworthiness value. Disregarding the WANposition estimate if the WAN position estimate and the access pointposition estimate are uncorroborated and the WAN base stationtrustworthiness value is lower than the access point trustworthinessvalue, outputting the access point position estimate and decreasing theWAN base station trustworthiness value.

An example of a system for transferring trust between network basestations according to the disclosure a base station database operativeto maintain a database identifying one or more WAN base stations andcorresponding WAN location information, and one or more access pointsand corresponding access point location information, such that the WANlocation information includes a WAN trustworthiness value for each ofthe WAN base stations, and the access point local information includesan access point trustworthiness value for each of the access points, aposition determination module configured to determine a WAN positionestimate for a mobile device based on the WAN location informationcorresponding to a WAN base station that is in communication with themobile device, determine an access point position estimate for themobile device based on the access point location informationcorresponding to an access point that is in communication with themobile device, an almanac processor configured to compare the WANtrustworthiness value associated with the WAN base station and theaccess point trustworthiness value associated with the access point,determine if the WAN position estimate and the access point positionestimate are corroborated, increase the access point trustworthinessvalue if the WAN position estimate and the access point positionestimate are corroborated and the WAN trustworthiness value higher thanthe access point trustworthiness value, and increase the WANtrustworthiness value if the WAN position estimate and the access pointposition estimate are corroborated and the WAN trustworthiness value islower than the access point trustworthiness value.

An example of an apparatus for transferring trust between networksaccording to the disclosure includes means for receiving WAN basestation information including a WAN base station trustworthiness value,means for determining a WAN position estimate for the mobile devicebased on the WAN base station information, means for receiving accesspoint information including an access point trustworthiness value, meansfor determining an access point position estimate for the mobile devicebased on the access point information, means for determining if the WANposition estimate and the access point position estimate arecorroborated, and means for increasing the access point trustworthinessvalue if the WAN position estimate and the access point positionestimate are corroborated and the WAN base station trustworthiness valueis higher than the access point trustworthiness value.

An example of a computer program product residing on aprocessor-executable computer storage medium according to the disclosureincludes processor-executable instructions configured to cause aprocessor to receive WAN base station information including a WAN basestation trustworthiness value, determine a WAN position estimate for themobile device based on the WAN base station information, receive accesspoint information including an access point trustworthiness value,determine an access point position estimate for the mobile device basedon the access point information, determine if the WAN position estimateand the access point position estimate are corroborated, and increasethe access point trustworthiness value if the WAN position estimate andthe access point position estimate are corroborated and the WAN basestation trustworthiness value is higher than the access pointtrustworthiness value.

An example of a method of using a mobile device to transfer trustbetween networks according to the disclosure includes receiving networkstation information from a plurality of base stations, determining afirst position estimate for a mobile device based on the network stationinformation, receiving network station information from a single basestation, such that the single base station is not one of the pluralityof base stations, determining a location of the single base station,determining if the first position estimate for the mobile device and thelocation of the single base station are corroborated, and increasing atrustworthiness value associated with the single base station if thefirst position estimate for the mobile device and the location of thesingle base station are corroborated.

An example of an apparatus for transfer trust between networks accordingto the disclosure includes a memory, a processor configured to receivenetwork station information from a plurality of base stations, determinea first position estimate for a mobile device based on the networkstation information, receive network station information from a singlebase station, such that the single base station is not one of theplurality of base stations, determine a location of the single basestation, determine if the first position estimate for the mobile deviceand the location of the single base station are corroborated, andincrease a trustworthiness value associated with the single base stationif the first position estimate for the mobile device and the location ofthe single base station are corroborated, such that the trustworthinessvalue is stored in the memory.

An example of an apparatus for transferring trust between networksaccording to the disclosure includes means for receiving network stationinformation from a plurality of base stations, means for determining afirst position estimate for a mobile device based on the network stationinformation, means for receiving network station information from asingle base station, such that the single base station is not one of theplurality of base stations, means for determining a location of thesingle base station, means for determining if the first positionestimate for the mobile device and the location of the single basestation are corroborated, and means for increasing a trustworthinessvalue associated with the single base station if the first positionestimate for the mobile device and the location of the single basestation are corroborated.

An example of computer program product residing on aprocessor-executable storage medium according to the disclosure includesprocessor-executable instructions configured to cause a processor toreceive network station information from a plurality of base stations,determine a first position estimate for a mobile device based on thenetwork station information, receive network station information from asingle base station, such that the single base station is not one of theplurality of base stations, determine a location of the single basestation, determine if the first position estimate for the mobile deviceand the location of the single base station are corroborated, andincrease a trustworthiness value associated with the single base stationif the first position estimate for the mobile device and the location ofthe single base station are corroborated.

An example of a method of determining the position of a mobile deviceaccording to the disclosure includes receiving a first network stationinformation from a first base station, including location informationand trustworthiness information for the first base station, receiving asecond network station information from a second base station, includinglocation information and trustworthiness information for the second basestation, determining if the location information for the first andsecond base stations corroborate with one another, determining a firstposition estimate for the mobile device based on the first and secondnetwork station information if the location information is corroborated,determining a second position estimate for the mobile device based onthe first network station information if the location information isuncorroborated and the trustworthiness value of the first base stationis higher than the trustworthiness of the second base station, anddetermining a third position estimate for the mobile device based on thesecond network station information if the location information isuncorroborated and the trustworthiness value of the second base stationis higher than the trustworthiness of the first base station.

An example of an apparatus for determining the position of a mobiledevice according to the disclosure includes means for receiving a firstnetwork station information from a first base station, includinglocation information and trustworthiness information for the first basestation, means for receiving a second network station information from asecond base station, including location information and trustworthinessinformation for the second base station, means for determining if thelocation information for the first and second base stations corroboratewith one another, means for determining a first position estimate forthe mobile device based on the first and second network stationinformation if the location information is corroborated, means fordetermining a second position estimate for the mobile device based onthe first network station information if the location information isuncorroborated and the trustworthiness value of the first base stationis higher than the trustworthiness of the second base station, and meansfor determining a third position estimate for the mobile device based onthe second network station information if the location information isuncorroborated and the trustworthiness value of the second base stationis higher than the trustworthiness of the first base station.

An example of an apparatus for determining the position of a mobiledevice according to the disclosure includes a memory, a processorconfigured to receive a first network station information from a firstbase station, including location information and trustworthinessinformation for the first base station, receive a second network stationinformation from a second base station, including location informationand trustworthiness information for the second base station, determineif the location information for the first and second base stationscorroborate with one another, determine a first position estimate forthe mobile device based on the first and second network stationinformation if the location information is corroborated, determine asecond position estimate for the mobile device based on the firstnetwork station information if the location information isuncorroborated and the trustworthiness value of the first base stationis higher than the trustworthiness of the second base station, determinea third position estimate for the mobile device based on the secondnetwork station information if the location information isuncorroborated and the trustworthiness value of the second base stationis higher than the trustworthiness of the first base station, and storea mobile device position in the memory, such that the mobile deviceposition is one of the first, second or third position estimates.

An example of a computer program product residing on aprocessor-executable computer storage medium according to the disclosureincludes processor-executable instructions configured to cause aprocessor to receive a first network station information from a firstbase station, including location information and trustworthinessinformation for the first base station, receive a second network stationinformation from a second base station, including location informationand trustworthiness information for the second base station, determineif the location information for the first and second base stationscorroborate with one another, determine a first position estimate forthe mobile device based on the first and second network stationinformation if the location information is corroborated, determine asecond position estimate for the mobile device based on the firstnetwork station information if the location information isuncorroborated and the trustworthiness value of the first base stationis higher than the trustworthiness of the second base station, determinea third position estimate for the mobile device based on the secondnetwork station information if the location information isuncorroborated and the trustworthiness value of the second base stationis higher than the trustworthiness of the first base station, and storea mobile device position in the memory, such that the mobile deviceposition is one of the first, second or third position estimates.

An example of a method of determining the position of a mobile deviceaccording to the disclosure includes receiving a request for networkstation information associated with one or more base stations, such thatthe network station information includes a trustworthiness value foreach base station, comparing the trustworthiness value for each basestation to a threshold value, utilizing the network station informationfor the one or more base stations that have a trustworthiness valueequal to or greater than the threshold value to calculate a position forthe mobile device, and outputting the position of the mobile device.

An example of an apparatus for determining the position of a mobiledevice according to the disclosure includes means for receiving arequest for network station information associated with one or more basestations, such that the network station information includes atrustworthiness value for each base station, means for comparing thetrustworthiness value for each base station to a threshold value, meansfor utilizing the network station information for the one or more basestations that have a trustworthiness value equal to or greater than thethreshold value to calculate a position for the mobile device, and meansfor outputting the position of the mobile device.

An example of an apparatus for determining the position of a mobiledevice according to the disclosure includes a memory, a processorconfigured to receive a request for network station informationassociated with one or more base stations, such that the network stationinformation is stored in the memory and includes a trustworthiness valuefor each base station, compare the trustworthiness value for each basestation to a threshold value, utilize the network station informationfor the one or more base stations that have a trustworthiness valueequal to or greater than the threshold value to calculate a position forthe mobile device, and output the position of the mobile device.

An example of a computer program product residing on aprocessor-executable computer storage medium according to the disclosureincludes processor-executable instructions configured to cause aprocessor to receive a request for network station informationassociated with one or more base stations, such that the network stationinformation includes a trustworthiness value for each base station,compare the trustworthiness value for each base station to a thresholdvalue, utilize the network station information for the one or more basestations that have a trustworthiness value equal to or greater than thethreshold value to calculate a position for the mobile device, andoutput the position of the mobile device.

Items and/or techniques described herein may provide one or more of thefollowing capabilities, as well as other capabilities no mentioned. Atrustworthiness values can be assigned to WAN base stations and accesspoints. The trustworthiness values associated with a WAN base stationcan be transferred to one or more access points. The trustworthinessvalues associated with an access point can be transferred to a WAN basestation. Trustworthiness values may be used in determining the positionof a mobile device. The position information associated with WAN basestations and access points with low trustworthiness values can beeliminated or down weighted in a position determination calculation. Theaccuracy of the position determination calculation can be improved. Thetechniques described herein can be implemented on both a network basedserver or within a handset using downloaded or discovered cellular data.Other capabilities may be provided and not every implementationaccording to the disclosure must provide any, let alone all, of thecapabilities discussed. Further, it may be possible for an effect notedabove to be achieved by means other than that noted, and a noteditem/technique may not necessarily yield the noted effect.

BRIEF DESCRIPTION OF THE DRAWING

The features, objects, and advantages of embodiments of the disclosurewill become more apparent from the detailed description set forth belowwhen taken in conjunction with the drawings, in which like elements bearlike reference numerals. Further, various components of the same typemay be distinguished by following the reference label by a dash and asecond label that distinguishes among the similar components. If onlythe first reference label is used in the specification, the descriptionis applicable to any one of the similar components having the same firstreference label irrespective of the second reference label.

FIG. 1 is a schematic block diagram illustrating an exemplary mobiledevice capable of receiving access point and WAN base station signals,in accordance with an implementation.

FIG. 2 is a system diagram illustrating certain features of a systemcontaining a mobile device capable of receiving access point and WANbase station signals, in accordance with an implementation.

FIG. 3 is a block diagram of an embodiment of a system for corroboratingand transferring trust between AP network and WAN base station almanacs.

FIG. 4 is a wireless network including an access point with a suspecttrustworthiness value.

FIG. 5 is a wireless network including a WAN base station with a suspecttrustworthiness value.

FIG. 6 includes exemplary data structures for location information.

FIG. 7 is a flow diagram of an embodiment of a process for utilizingtrustworthiness factors when providing a position estimate.

FIG. 8 is a flow diagram of an embodiment of a process for transferringtrust between access points.

FIG. 9 is a flow diagram of an embodiment of a process for transferringtrust between access points and WAN base stations.

FIG. 10 is a flow diagram of an embodiment of a process for transferringtrust between WAN base stations and access points based a comparison ofa position estimate for a mobile device and the location of a single WANbase station and access point.

FIG. 11 is a flow diagram of an embodiment of a process for determininga position of a mobile device based on network station informationreceived from a first and a second base station.

FIG. 12 is a flow diagram of an embodiment of a process for sendingnetwork station information based on a trustworthiness value.

DETAILED DESCRIPTION

A method and system are disclosed that allow for dynamically updatingone or more almanacs associated with AP networks and wide area networks.A cellular network is an example of wide area network. In general, asmobile devices travel they can receive location information on variousaccess points (i.e., short range wireless transceivers) and WAN basestations (e.g., cell phone towers, WAN access points). The location andidentifying information associated with the various transceivers such asaccess points, femtocells and base stations may be contained in analmanac of transceivers. The received almanac information can beutilized along with received signals from transceivers in the almanac todetermine a location of a mobile device. For example, an almanac oralamanacs, may store transceiver locations, identifying information,device type, frequency and/or other related information used todetermine the position of a mobile device. MAC addresses, or otheridentifying information (e.g., SSIDs, Index Numbers) for access pointsmay be included as part of almanac entries. A trustworthiness levelwhich generally indicates the confidence with which the locationinformation in an almanac can be used in the location calculations mayalso be included in an almanac. A trustworthiness level can beassociated with difference sources of geographical location information(e.g., satellite, WAN, and AP fixes). When multiple location fixes canbe obtained, the trustworthiness levels associated with the fixes can bedetermined. In general, if the calculated locations for each of thefixes do not correspond to one another, the position results with thelowest trustworthiness level can be discarded, and/or an alert can begenerated. Alternatively, in some embodiments, information tied toparticular transceivers may be discarded from or de-weighted in alocation calculation if they add too much error and/or uncertainty tothe calculated location.

In an example, the trustworthiness level of an access point that hasmoved, or has been recently added to a network, may be relatively low.The trustworthiness levels associated with the access points and the WANbase stations can be compared. Access points and base stations with lowtrustworthiness levels can be removed from the location calculations orde-weighted in calculations. The trustworthiness level of a an accesspoint or WAN base station may be increased or decreased based on theresults of the comparison of locations using information from a lesstrustworthy station versus the comparison of a location calculated usingonly more trustworthy stations. Similarly, a station may be deemedtrustworthy if it does not significantly increase the estimated errorassociated with a location calculation and untrustworthy if it addssignificantly to the estimated error associated with a locationcalculation, such as that determined by performing a least squares fitof the data. For example, if the position estimates from the differentstations corroborate to one another, the trustworthiness level of one orall the stations can be increased.

Referring to FIG. 1, a mobile device 100 may contain one or morewireless transceiver(s) 121 which are capable of sending and receivingwireless signals over communication links 123, 132 via wirelessantenna(s) 122 over a wireless network and connected to a bus 101 by awireless transceiver bus interface 120. The wireless transceiver businterface 120 may, in some embodiments be a part of the wirelesstransceiver (s) 121. Some embodiments may have multiple wirelesstransceivers 121 and wireless antennas 122, for example, to supportmultiple wireless standards such as WAN standards such as CDMA, GSM,CDMA 2000, WCDMA, UMTS, and LTE and Wireless LAN and short rangewireless standards such as WiFi, Bluetooth and Zigbee.

In certain embodiments of mobile device 100 may contain a SatellitePositioning System (SPS) receiver 155 capable of receiving SatellitePositioning System (SPS) signals 159 via SPS antenna 158. SPS receiver155 may also process, in whole or in part, the Satellite PositioningSystem (SPS) signals 159 and use the SPS signals 159 to determine thelocation of the mobile device. In some embodiments, general-purposeprocessor(s) 111, memory 140, DSP(s) 112 and specialized processors (notshown) may also be utilized to process the SPS signals 159, in whole orin part, and/or calculate the location of the mobile device 100, inconjunction with SPS receiver 155. The storage of SPS or other locationsignals may be done in memory 140 or registers. An audiointerface/output 135 can be included in mobile device 100 to convertsignals to audible sound to enable transmission of the audible sound tothe user.

The mobile device 100 may contain DSP(s) 112 connected to the bus 101 bya bus interface 110, general-purpose processor(s) 111 connected to thebus 101 by a bus interface 110 and memory 140, also sometimes connectedto the bus by a bus interface 110. The bus interfaces 110 may beintegrated with the DSP(s) 112, general-purpose processor(s) 111 andmemory 140 with which they are associated. In various embodiments,functions may be stored as one or more instructions or code in memory140 such as on a computer-readable storage medium, such as RAM, ROM,FLASH, or disc drive, and executed by general-purpose processor(s) 111,specialized processors, or DSP(s) 112. Memory 140 is aprocessor-readable memory and/or a computer-readable memory that storessoftware code (programming code, instructions, etc.) configured to causethe processor(s) 111 and/or DSP(s) 112 to perform functions described.

In other embodiments, functions may be performed in hardware.

Referring to FIG. 2, a mobile device 100 may receive SPS signals 159from SPS Satellites 260. In some embodiments, the SPS Satellites may befrom one global navigation satellite system (GNSS), such as the GPS orGalileo satellite systems. In other embodiments, the SPS Satellites maybe from multiple GNSS such as, but not limited to, GPS, Galileo,Glonass, or Beidou (Compass) satellite systems. The receiving andprocessing of SPS signals 159 is optional and not a limitation. In anembodiment, mobile devices without SPS capabilities may be used.

The mobile device 100 may query a location server 250 via an accesspoint (i.e., short range wireless transceiver) 210, or a WAN basestation 220, which may be connected via a network 230 such as theInternet. The configuration of the location server 250 is exemplaryonly, and not a limitation. In an embodiment, the location server may beconnected directly to the WAN base station 220. More than one locationserver may be used. In other embodiments, a centralized location servermay be used to support multiple wireless transceivers and base stations.The location server 250 includes one or more almanacs (i.e., databases)containing location information associated with base stations on anetwork. The location information may be associated with one or moreaccess points 210, and/or one or more WAN base stations 220. In anexample, the location server 250 is comprised of multiple server unitssuch as a base station almanac and an access point almanac.

Referring FIG. 3, a block diagram of an embodiment of system 300 forcorroborating and transferring trust between AP and WAN databases isshown. The system 300 allows a mobile device 100 to find a geographiclocation by WAN base stations 312, and one or more access points 324. Inan embodiment, the mobile device 100 can communicate with one or moreWAN base stations 312 and access points 324 to provide locationinformation. The WAN base stations 312 and access points 324 can becoupled to an almanac processor 322 via a network 310. In an embodiment,the network 310 can include the Internet. The almanac processor 322 canaccess a Position Determination Module (PDM) 340 and base stationalmanac 344 a and/or access point almanac 344 b to analyze and processthe location information. The PDM 340 can determine and output positionestimate based on the location information. Information in the basestation almanac 344 a and the access point almanac 344 b can persist ina single database (e.g., location server 250), or in separate databasesas shown in FIG. 3. Once analyzed and processed, the almanacs 344 (i.e.,the base station almanac 344 a and the access point almanac 344 b) canbe updated according to the trustworthiness values associated with theWAN base stations 312 and access points 324 respectively.

In an embodiment, the mobile device 100 can communicate with one or moreWAN base stations 312 and access points 324 to provide locationinformation. In an embodiment, the mobile device 100 is a cellular phonethat may have any number of communication modes (e.g., GSM, CDMA,digital AM or FM radio, digital TV, TDMA, WCDMA, OFDM, GPRS, EV-DO,WiFi, Bluetooth, WiMAX, UWB, satellite phone or data, etc.) to transfervoice and/or data with cellular, satellite and/or mesh networks by wayof the WAN base stations 312, and the and access point 324. In general,WAN base stations 312 and access points 324 can allow some sort of dataor voice transport. The identifier in the case of a WAN base station 312may be a System ID (SID), a Network ID (NID), a Base Station ID (BSID)and/or latitude and longitude information. The identifier in the case ofan access point 324 may be a Service Set Identifier (SSID) and/or a MACaddress.

In some cases, the access points 324 move too frequently to be usefulfor determining the location of the mobile device 100. For example, theowners of access points 324 are generally free to move the hardware(i.e., the wireless transceivers) to suit their needs and the locationof the access points 324 may not be recorded in a database. In general,the position information associated with access points 324 can be storedwithin the access point almanac 344 b. For example, each access point324 may include a SSID and/or MAC address as identifier information.Other characteristics of the WAN base stations 312 and access points 324could be used in uniquely identifying the WAN base station 312 andaccess points 324 respectively. For example, if two WAN base stations,or access points, had the same station identifier, but only onesupported a particular communication standard, the two could be uniquelyidentified. Also stored in the base station almanac 344 a and the accesspoint almanac 344 b is location information that is associated with theWAN base stations 312 and access points 324 respectively. As an example,and not a limitation, the location information can be determined foreach WAN base station 312 or access point 324 by performing surveys ofthe area, for example, with wireless devices and/or with GNSS-enabledsurvey equipment. The location information can include a trustworthinessvalue for each WAN base station 312 and access point 324. Thetrustworthiness value can be a numerical value between 0 and 1 (e.g., apercentage), or other values which can be compared to determine arelative difference. For example, a location of a particular WAN basestation 312 may be known and thus will have a high trustworthinessvalue, and location of an access point 324 may be based on an estimateand therefore will have a low trustworthiness level. The opposite mayalso be true. The location information stored in the respective almanacs344 a, 344 b for each of the WAN base stations 312 and access points 324can be used to determine the trustworthiness of a position estimate fora mobile device 100. The almanacs 344 a, 344 b may also be used tomodify the trustworthiness levels associated with a particular WAN basestation 312 or access point 324 based on the trustworthiness levels ofother WAN base stations 312 or access points 324 that are received bythe mobile device 100. This embodiment shows the almanac processor 322is separate from the WAN base stations 312, and access points 324, butin other embodiments, each cooperative WAN base station 312 and accesspoint 324 could have an almanac processor 322.

The almanac processor 322 could be implemented with a computer ornetwork of computers either in a single location or distributed across anumber of locations. The almanacs 344 a, 344 b could be centrallylocated, but other embodiments could distribute the almanacs 344 a, 344b regionally or in portions relevant to a particular WAN base station312, or particular access point 324. The base station almanac 344 a andthe access point almanac 344 b can be a single almanac. In an example, afirst WAN base station 312-1, may store a portion of the base stationalmanac 344 a for its footprint and all adjacent base station footprintsas a local almanac 358-1. The footprint can be based on the MaximumAntenna Range (MAR) of a base station, or other geographic constraintswhich may impact the operational performance of the base station. As thevarious local almanacs 358 are updated, those changes are propagated tothe centrally-located base station almanac 344 a.

Referring to FIG. 4, with further reference to FIG. 3, a wirelessnetwork 400 including an access point 324-4 with a suspecttrustworthiness value is shown. The mobile device 100 is configured toreceive signals from the WAN base station 312, and the access points324-1, 324-2, 324-3, 324-4 (collectively referred to as 324). Each ofthe WAN base station 312 and access points 324 includes an area ofcoverage 312-F, 324-F (e.g., 312-F-1, 324-F-1, 324-F-2, 324-F-3,324-F-4) respectively. In this example, the area of coverage for each ofthe WAN base station and access points is shown as a circular shape, butother geometric shapes may be used. The area of coverage can be computedor determined by a survey and stored in the almanacs 344 a. 344 b. Themobile device 100 is within the footprint 312-F-1 of the WAN basestation 312-1. The location of the WAN base station 312-1 is known andmaintained by a service provider and therefore the trustworthiness levelassociated with the WAN base station 312-1 can be relatively high (e.g.,0.80, 0.90, 0.95, 0.98). The mobile device also detects a MAC addressfor each of the four access points 324. The corresponding footprints324-F for each of the access points 324 can be stored in the almanacs344 a, 344 b and a position estimate can be determined based on theoverlapping footprints 324-F. In some situations, the trustworthinesslevel associated with each of the access points 324 may be relativelylow (e.g., 0.5, 0.4, 0.1) due to the mobility associated with the accesspoint hardware, or potential issues with the data in the almanac (e.g.,stale data, inaccurate location of the antenna, use of a generalfootprint model).

In an embodiment, the almanac processor 322 can execute an algorithm tocross-check the trustworthiness level for the WAN base station 312-1(i.e., a WAN base station trustworthiness level) with thetrustworthiness level for each of the access points 324, or atrustworthiness level associated with an estimated position based on theaccess points 324 (i.e., an access point trustworthiness level). In thisexample, the trustworthiness level of the WAN base station 312 is higherthan the trustworthiness values of the access points 324. If theestimated locations of the access points 324 correspond with the knownlocation of the WAN base station 312-1, then the trustworthiness levelfor each of the access points can be increased. That is, the trust inthe location information for the WAN base station 312-1 can be imputedto the access points 324. The corresponding data in the almanac 344 bcan be updated accordingly. Conversely, if the estimated locations ofthe access points 324 did not corroborate with the WAN base station 312,then the trustworthiness levels associated with one or more of theaccess points 324 can be decreased.

An example of decreasing the trustworthiness level of an access pointcould be as follows. The location information in the access pointalmanac 344 b for access point 324-4 indicates that access point 324-4is miles away from WAN base station 312-1 and the access points 324-1,324-2, 324-3. The MAC address for access point 324-4, however, isdetected by the mobile device 100 concurrently with the BSID for WANbase station 312-1, and the MAC addresses for access points 324-1,324-2, 324-3. Thus, the corresponding location and footprint informationdoes not corroborate with either the WAN base station 312, or the accesspoints 324-1, 324-2, 324-3 (e.g., the access point 324-4 may have beenmoved from a previous location to the location as shown in FIG. 4, orthe data in the access point almanac 344 b may be corrupted). The actualaccess point footprint 324-F-4 on FIG. 4 is depicted with a dashed lineto highlight that the mobile device 100 is detecting the uncorroboratedaccess point 324-4. In this scenario, the trustworthiness level of onlyaccess point 324-4 is decreased and its corresponding locationinformation can be removed from the position estimate process. In anembodiment, after a number of detection cycles, the trustworthinesslevel of access point 324-4 can be increase. For example, if the accesspoint 324-4 is repeatedly detected and corroborated with the WAN basestation 312-1, and the other access points 324-1, 324-2, 324-3.

Referring to FIG. 5, with further reference to FIGS. 3 and 4, a wirelessnetwork 500 including a WAN base station 312-2 with a suspecttrustworthiness value is shown. In some regions of the world, thetrustworthiness of location data in an almanac for WAN base stations 312can be less than that of access points 324. In the network 500, forexample, the mobile device 100 can receive station identifyinginformation (e.g., BSA, SSID, MAC addresses) from WAN base stations312-1, 312-2, and access points 324-1, 324-2, 324-3. The almanacprocessor 322 can receive the station identifying information anddetermine if the associated location information in the almanacs 344 a,344 b for each of the WAN base stations 312-1, 312-2 and the accesspoints 324-1, 324-2, 324-3 corroborate with one another. Thetrustworthiness values and location information associated with thefirst WAN base station 312-1, and the access points 324-1, 324-2, 324-3are corroborated and thus the corresponding almanac information can beused to create an estimated position. If the mobile device 100 alsodetects identifying information for a second WAN base station 312-2, thetrustworthiness value for the WAN base station 312-2 can be compared tothe WAN base station 312-1 and the access points 324-1, 324-2, 324-3. Ifthe trustworthiness level of the second WAN base station 312-2 isrelatively low, and the extent of the footprint 312-F-2 is not known,the location information associated with the WAN base station 312-2 maynot be used in determining a position estimate.

In an embodiment, the trust in the location information associated withan AP network can be transferred to a WAN base station. In an examplealgorithm, the trustworthiness levels associated with the access points324-1, 324-2, 324-3 can be used to increase the trustworthiness level ofthe suspect WAN base station 312-2. For example, the mobile device 100can detect the MAC addresses for the access points 324-1, 324-2, 324-3and a base station address for the second WAN base station 312-2. Theaccess points 324-1, 324-2, 324-3 may have a higher trustworthinesslevel than the second WAN base station 312-2. If the locationinformation associated with the second WAN base station 312-2corroborates with the location information of the access points 324-1,324-2, 324-3, the trustworthiness level of the second WAN base station312-2 can be increased.

Referring to FIG. 6, with further reference to FIG. 3, an exemplary datastructure 600 for location information is shown. The data structure 600is exemplary only and not a limitation as additional tables and fieldsmay be used. The data structure 600 can persist in a base stationdatabase and can include a base station almanac 602 and an access pointalmanac 606. The base station almanac 602 may contain WAN base stationinformation, and the access point almanac 606 may contain access pointinformation. For example, the almanacs 602, 606 can be one or morerelational databases with a collection of tables. The location server250 can include a relational database comprising a base station almanac602 and an access point almanac 606. Some or all of the data within thealmanacs 602, 606 may also be stored on the mobile device 100. Thealmanacs 602, 606 can include one or more tables (i.e., data structures)604, 608 containing data fields for location information. The datafields can be of data types as known in the art (e.g., number, char,varchar, date, etc. . . . ). The base station almanac 602 may caninclude multiple fields to represent a WAN base station such as a BSID,the latitude and longitude of a base station, the coverage area (e.g.,footprint) of a base station, an uncertainty value, and atrustworthiness value. Other fields such as the WAN base station'saltitude and other operating and signal parameters may also be used. Theaccess point almanac 606 may can include multiple fields to represent anaccess point such as a SSID, MAC address, the latitude and longitude ofa access point, the coverage area (e.g., footprint) of an access point,an uncertainty value, and a trustworthiness value. Other fields such asthe access point's altitude and other operating and signal parametersmay also be used. In an embodiment, the data structures 604, 608 can becombined within a single table.

In operation, referring to FIG. 7, with further reference to FIG. 3, aprocess 700 for utilizing trustworthiness factors when providing aposition estimate using the system 300 includes the stages shown. Theprocess 700, however, is exemplary only and not limiting. The process700 may be altered, e.g., by having stages added, removed, orrearranged.

At stage 702, a mobile device 100 can receive ID information (e.g.,SSID, MAC address) for one or more access points in an AP network. In anembodiment the mobile device 100 does not, or cannot, participate on aWAN but is capable of receiving signals from access points 324. Inanother embodiment, the mobile device 100 is on a WAN (e.g., cellularnetwork) and can be configured to utilize a MS-Assisted (MS-A) callflow. Other call flows and messaging systems may also be used. At stage704, a process decision is made based on the availability of WANsignals. If WAN base station information is not received, the processdetermines a position estimate based on the received AP network signals.The mobile device 100 can communicate with the location server 250 viathe network 230. The location server 250 can include a positiondetermination module 340, an almanac processor 322, and almanacs 344 a,344 b.

At stage 706, the trustworthiness value for each detected access pointis determined. The trustworthiness values can be stored in an almanac onthe location server 250 or may be stored locally in the mobile device100. The trustworthiness value can be a field within a data structure608 that is associated with a particular access point (e.g., via a MACaddress or other base station identifier).

At stage 708, a position estimate based on location informationassociated with the detected access points can be calculated. The datastructure 608 can include location information such as the latitude andlongitude of the received access point, an expected footprint, anuncertainty factor, and a trustworthiness factor. In an embodiment, anestimated position can be calculated by determining the intersection ofthe coverage areas. Other positioning techniques such as trilaterationmay be used. An uncertainty value may also be applied to the positionestimate. In an embodiment, the trustworthiness factor of each stationis used to calculate the position estimate. For example, access pointswith trustworthiness values which are below a predetermined thresholdcan be eliminated from the position estimate. The trustworthiness valuescan be used to weight the position calculation such that theuntrustworthy stations have a smaller impact on the final positionestimate. At stage 710, the position estimate can be output to anotherapplication (e.g., displayed to the user, utilized by other locationbased services).

When the mobile device 100 is in a WAN, the location informationprovided by a WAN base station 312 may be used in the position estimate.At stage 712, the trustworthiness value of one or more WAN base stations312 is determined. The trustworthiness levels for the access points 324are also determined. The trustworthiness levels may be stored onalmanacs 344 a, 344 b, 358 or locally on the mobile device 100. At stage714 a position estimate is calculated based on the trustworthinesslevels of all of the received WAN base stations 312 and access points324. WAN base stations and access points with low trustworthiness levelscan be removed from the position determination calculation, or otherwisediminished through a weighting function. The calculation can utilize thealmanac data to determine an intersection of coverage areas, comparereceived signal strengths, perform trilateration operations, or otherposition determining techniques as known in the art. The positionestimate can be provided (i.e., output) to the user, or otherapplication, at stage 718.

In operation, referring to FIG. 8, with further reference to FIG. 3, aprocess 800 for transferring trust between access points using thesystem 300 includes the stages shown. The process 800, however, isexemplary only and not limiting. The process 800 may be altered, e.g.,by having stages added, removed, or rearranged.

At stage 802, a mobile device can receive network station informationfrom two or more access points 324. In an embodiment, the mobile device100 can cross reference an access point MAC address, or other accesspoint identifier, with a remote or local almanac (e.g., access pointalmanac 344 b). Location information associated with the access pointcan be retrieved for use in a position estimating process. The positionestimating process can occur locally (i.e., on the mobile device 100) oron a remote location server 250. At stage 804 the position determinationmodule 340, or the mobile device 100, can determine one or more positionestimates based on the received access points 324. For example, theposition estimate for an access point 324 may be an area defined by thefootprint 324-F of the access point. In an embodiment, the positionestimate for a particular access point 324 can be based on the receivedsignal strength, or other positioning techniques. An uncertainty valuecan be used in the positioning process. An exemplary algorithm canutilize the information contained in the access point almanac 344 bassociated with the access points 324 to determine one or more estimatedpositions of the mobile device 100. The algorithm can then compare theposition estimates associated with the access points 324 with oneanother at stage 806. For example, the comparison may determine whetherthe footprints 324-F overlap, or determine a distance between theestimated positions.

At stage 810 a decision is made on whether the position estimatescorroborate with one another. Determining if the position estimatescorroborate can occur on remote location server 250, or on the mobiledevice 100. The corroboration of position estimates can mean that theone or more estimated positions of the mobile device 100 based thereceived access points 324 are within an acceptable distance from oneanother. A corroborated position can mean that the mobile device 100 iswithin the expected footprints 324-F of each of the access points 324.Other multivariate corroboration or correlation techniques may be usedto analyze the position estimates and determine if any results areoutliers for the group. For example, an uncorroborated positionestimated can be one that is outside the footprint 324-F of the otheraccess points, or returns a position estimate that is a distance awayfrom the other position estimates. Moving the location of an accesspoint without updating the corresponding location information (e.g.,lat./long./alt., area) can lead to an uncorroborated position estimate.Other database errors or signal strength issues may also create anuncorroborated position estimate.

If one or more of the position estimates do not corroborate, thecorresponding access point 324 are identified at stage 812. Once anaccess point 324 is identified, the trustworthiness value for the accesspoint 324 can be decreased at stage 814. As previously discussed, anaccess point (or WAN base station) with a decreased trustworthinessvalue can be removed from a position estimating process, or downweighted to reduce its contribution to the final position estimate.

Stages 816 and 818 are optional. In an embodiment, if the mobile device100 is within the footprint 312-F-1 of a WAN base station 312-1, thenone or more position estimates based on the WAN base station informationcan be used in the comparison at stage 806.

Stage 820 is optional. In an embodiment, if the position estimates ofthe access points 324 corroborate to one another, then their respectivetrustworthiness values can be increased by some amount. As discussed, anincrease in trustworthiness can impact subsequent position estimatecalculations. If a network includes both WAN base stations 312 andaccess points 324, the trust from the WAN base stations 312 can betransferred to the access points 324. For example, assuming that aposition estimate of a high trustworthiness WAN base station is includedin the comparison at stage 806, and the position estimates derived fromthe WAN base station(s) 312 and the low trustworthiness access point(s)324 (i.e., only one access point is needed for this example)corroborate, then the trustworthiness factor of the access point 324 canbe increased up to the level of trustworthiness for the WAN base station312.

In operation, referring to FIG. 9, with further reference to FIG. 3, aprocess 900 for transferring trust between access points and WAN basestations using the system 300 includes the stages shown. The process900, however, is exemplary only and not limiting. The process 900 may bealtered, e.g., by having stages added, removed, or rearranged.

A mobile device 100 can receive network station information from WANbase stations 312 and access points 324 at stages 902 a and 902 b.Position estimates based on the location information (e.g., almanac datastructures 604, 608) associated with the WAN base stations 312 andaccess points 324 can be determined at stage 904 a and 904 b. Theprocessing of the location information can occur remotely on a locationserver 250, locally on the mobile device 100, or on a combination ofboth. For example, the position estimates derived from the WAN basestations 312 can be determined on the location server 250, and theposition estimates derived from the access points 324 can be determinedon the mobile device 100. Processors from other computers on the systemmay also be used. The position estimates from the WAN base stations 312and access points 324 can be compared at stage 906. The comparison canoccur on the mobile device 100 or on the location server 250.

A corroboration detection process such as previously described can occurat stage 908 and a decision on whether the position estimates arecorroborated may be made. In an embodiment, the trust in a WAN networkcan be transferred to an AP network. Similarly, the trust in an APnetwork can be transferred to a WAN network. For example, if theposition estimates corroborate with one another at stage 908, then thetrustworthiness values of the access points and the WAN base stationscan be increased. At stage 910, if the access points 324 have a highertrustworthiness value in relation to the WAN base stations 312, then thetrustworthiness values associated with the WAN base stations 312 can beincreased. Correspondingly, if the access points 324 have relatively lowtrustworthiness values, they can be increased based on thetrustworthiness values of the WAN base stations 312. In an embodiment,the trustworthiness value for each of the WAN base stations 312 and theaccess points 324 can be increased. The increase in trustworthinessvalue can occur if additional conditions are met. For example, theposition estimates must be within a certain range, the received signalstrengths must meet a minimum value, or a minimum number of stationsmust be detected. Other conditions directed to the accuracy of theposition estimate may also be used. For example an operator may manuallyupdate the trustworthiness level (i.e., human intervention).

At stage 912, if the position estimates are uncorroborated, then theuncorroborated access points 324 or WAN base station 312 can bedisregarded and the comparison can repeat without that disregardedstation. In an embodiment, if the corroboration process indicates thatthere are more than one uncorroborated WAN base station 312 and accesspoints 324, then WAN base station 312 or access point 324 station withthe lowest trustworthiness level can be disregarded. The process caniterate through the WAN base stations and access points in order of thetrustworthiness levels until a corroboration exists, or a no solutiondetermination is made (i.e., the number of remaining WAN base stationsand access points is below a minimum). If a WAN base station or accesspoint is disregard for a subsequent comparison at stage 912, then thetrustworthiness level of that WAN base station or access point can bedecreased at stage 914.

In operation, referring to FIG. 10, with further reference to FIG. 3, aprocess 1000 for transferring trust between WAN base stations 312 andaccess points 324 based a comparison of a position estimate for a mobiledevice 100 and the location of a single WAN base station or access pointis shown. The process 1000, however, is exemplary only and not limiting.The process 1000 may be altered, e.g., by having stages added, removed,or rearranged.

At stage 1002 the position determination module 340, or the mobiledevice 100, can receive network station information from a plurality ofWAN base stations 312 and access points 324. The notation BS(1) . . .BS(n) on FIG. 10 is used to indicate that a base station (BS) can beeither a WAN base station 312 or an access point 324. For example, BS(1)can be WAN base station 312-1, BS(2) can be access point 324-1, andBS(3) can be WAN base station 312-2. Other combinations of WAN basestations 312 and access points 324 can be used. The network stationinformation can include one or more of the data fields contained in thedata structure 600. For example, the mobile device 100 can receive theMAC addresses, SSID, and/or Base Station IDs (i.e., address information)from a plurality of base stations (e.g., BS(1), BS(2), BS(3) . . .BS(n)), and then transmit that information over the communication link132. The position determination module 340 can receive the addressinformation and then query the base station almanac 344 a and accesspoint almanac 344 b to receive the associated fields in the datastructure 600.

At stage 1004, the received network station information may be processedto determine a position of the mobile device 100. In an embodiment, aposition determining algorithm can be executed on the positiondetermination module 340 (i.e., remotely). The position determiningalgorithm can also be executed on the mobile device 100 (i.e., locally).For example, a positioning determining algorithm can utilize thereceived signal strength of the base stations (e.g., BS(1), BS(2), BS(3). . . ), or an estimated position can be calculated by determining theintersection of the coverage areas for the base stations. Otherpositioning algorithms such as trilateration may also be used. In anembodiment, the algorithm can use the trustworthiness factor of eachbase station (e.g., BS(1), BS(2), BS(3) . . . ) to calculate theposition estimate. For example, stations with trustworthiness valueswhich are below a predetermined threshold can be eliminated from theposition estimate. The trustworthiness values can be used to weight theposition calculation such that the untrustworthy stations have a smallerimpact on the final position estimate.

At stage 1006 the position determination module 340, or the mobiledevice 100, can receive network station information from a single WANbase station 312 or access point 324. The notation BS(x) on FIG. 10 isused to indicate that the base station BS(x) can be either a WAN basestation 312 or an access point 324. The notation BS(x) may also indicatea serving cell or sector associated with a WAN base station 312. Forthis example, the single base station BS(x) is not one of the pluralityof base stations BS(1) . . . BS(n) described in stage 1002. The receivednetwork station information can include one or more of the data fieldscontained in the data structure 600. For example, the mobile device 100can receive the MAC addresses, SSID, and/or Base Station ID (i.e.,address information) from the base station BS(x), and then transmit thatinformation over the communication link 132. The position determinationmodule 340 can receive the address information and then query the basestation almanac 344 a and access point almanac 344 b to receive theassociated fields in the data structure 600. For example, at stage 1008,the data structure 600 includes geographic coordinates (e.g., latitudeand longitude) and a coverage area for the base station BS(x). Theposition determination module 340, or the mobile device 100, can utilizethis information to determine the expected location and coverage area ofthe single base station BS(x) (i.e., the location as stored in thealmanac 344 a, 344 b).

At stage 1010 the location of the mobile device 100 is compared to thelocation and coverage area of the single base station BS(x). In general,the coverage area of any base station indicates the range or footprintof the base station. A mobile device that is located within coveragearea of a base station can communicate with the base station. Thecoverage area can be polygon or other representation of a geographicarea that is stored in the data structure 600. The coverage area mayalso be computed based on expected transmission performance as known inthe art. For example, the expected coverage area of a WAN base station312-1 can be defined by a circle 312-F-1 with a radius of 1 km, and theexpected coverage area of an access point 324-1 can be defined by acircle 324-F-1 with a radius of 100 m. Other radius values may be usedto determine the coverage area of a base station. For example, a WANbase station 312 may be a serving cell and the coverage area is definedby a sector. The position determination module 340, or mobile device100, can utilize a spatial comparison or distance determinationalgorithms to compare the position of the mobile device (e.g., ascalculated using network station information associated with basestations BS(1) . . . BS(n)) with the coverage area of the single basestation BS(x). At stage 1012 the position determination module 340 (orthe mobile device 100) can determine whether the position of the mobiledevice 100 corroborates with the position of the single base stationBS(x). The corroboration can mean that the mobile device 100 is withinthe expected coverage area of the single base station BS(x).

If the position of the mobile device 100 and the single base stationBS(x) corroborate with one another, than at stage 1014 the positiondetermination module 340 utilizes position determination algorithm andthe network station information from both the plurality of base stations(i.e., BS(1) . . . BS(n)) and the single base station (i.e., BS(x)) todetermine the position of the mobile device 100. As previouslydescribed, the position determination algorithm can utilize thetrustworthiness values to determine the position of the mobile device100. For example, if the trustworthiness value of the single basestation BS(x) is higher than the trustworthiness values associated withone or more the plurality of base stations BS(1) . . . BS(n), then theposition determined at stage 1014 can be based on the networkinformation associated with the single base station BS(x) and only aportion of the plurality of base stations BS(1) . . . BS(n). That is,the less trustworthy base stations can be eliminated (or otherwisedowngraded) from the position determination calculation.

At stage 1020, if the trustworthiness of the single base station BS(x)is lower than the trustworthiness of the plurality of the base stationsBS(1) . . . BS(n), either individually or collectively, then thetrustworthiness value of the single base station BS(x) can be increased.Stage 1020 is optional and not a limitation. The amount of the increasecan vary by implementation. In one example, the position determinationmodule 340 can transfer the trustworthiness values of the plurality ofbase stations BS(1) . . . BS(n) to the single base station BS(x) (i.e.,the trustworthiness values would be equal). In an embodiment, thetrustworthiness value of the single base station BS(x) can be a weightedaverage based on the number of position calculations. For example, thetrustworthiness value of BS(x) can increase a fixed amount (e.g., 0.05,0.1, 0.15, etc. . . . ) for each successful corroboration at stage 1012,with an upper limit being the trustworthiness value associated with theplurality of base stations BS(1) . . . BS(n).

At stage 1016, if the position of the mobile device 100 does notcorroborate with the location of the single base station BS(x), then thenetwork station information associated with BS(x) is not used in theposition determination calculation. For example, if the single basestation BS(x) is physically moved and the almanac data is not updated toreflect the change in location, or the almanac data is otherwisecorrupted, then the location data associated with BS(x) should not beused in the position determination algorithm.

At stage 1018, the trustworthiness value of the single base stationBS(x) can be decreased. The amount of the decrease can vary based on theimplementation. In an example, the position determination module 340 canset the trustworthiness value of the uncorroborated BS(x) to zero, oranother value that is lower than the trustworthiness values associatedwith the plurality of base stations BS(1) . . . BS(n). The positiondetermination module 340 may utilize a weighted average algorithm todecrease the trustworthiness value of BS(x). That is, for each positionrequest in which the position of the mobile device and the location ofBS(x) are uncorroborated, the trustworthiness value for BS(x) candecrease a fixed amount (e.g., 0.05, 0.1, 0.15, etc. . . . ).

In operation, referring to FIG. 11, with further reference to FIG. 3, aprocess 1100 for determining a position of a mobile device based onnetwork station information received from a first and a second basestation is shown. The process 1100, however, is exemplary only and notlimiting. The process 1100 may be altered, e.g., by having stages added,removed, or rearranged.

At stages 1102 and 1104, a mobile device 100 receives networkinformation associated with a first and second base stationrespectively. In an embodiment, the position determination module 340receives the network station information. The base stations in thisexample can be a WAN base station 312, an access point 324, or acombination of both. The network station information can include one ormore of the data fields contained in the data structure 600. Forexample, the mobile device 100 can receive the MAC addresses, SSID,and/or Base Station IDs (i.e., address information) from first andsecond base stations, and then transmit that information over thecommunication link 132. The position determination module 340 canreceive the address information and then query the base station almanac344 a and access point almanac 344 b to receive the associated fields inthe data structure 600.

At stage 1106, the position determination module 340 is configured tocompare the locations associated with the first and second basestations. For example, a geographical location such as latitude andlongitude is included in the data structure 600 and the positiondetermination module can utilize a distance algorithm to determine adistance between each of the base stations. The position determinationmodule 340 can also be configured to determine an overlap in thecoverage areas for each of the first and second base stations. At stage1108, the position determination module 340 can determine if thelocations of the first and second base stations corroborate with oneanother. In an embodiment, the locations can corroborate with oneanother if the locations are within a predefined distance from oneanother, or if their respective coverage areas overlap.

At stage 1110, if the locations of the first and second base stationscorroborate with one another then the position determination module 340may be configured to execute a position determination algorithm todetermine a position of the mobile device based on the network stationinformation received from the first and second base stations. Theposition determination algorithm can utilize the trustworthiness valuesto determine the position of the mobile device 100. For example, if thetrustworthiness value of the first base station is higher than thetrustworthiness values associated with the second base station, then theposition determined at stage 1110 can be weighted to favor the valuesassociated with the first base station. That is, in an embodiment, thecontribution of a corroborated but less trustworthy base station can beeliminated (or otherwise downgraded) from the position determinationcalculation.

At stage 1112, if the locations of the first and second base stations donot corroborate one another, and the position determination module 340is configured to determine which of the two base stations has a highertrustworthiness value. For example, an algorithm can compare thetrustworthiness values that are associated with the first and secondbase stations. If the first base station has a higher trustworthinessvalue, then at stage 1114 the position determination module 340 utilizesthe network station information associated with the first base stationto determine the location of the mobile device 100. Conversely, if thesecond base station has a higher trustworthiness value, then at stage1116, the position determination module 340 utilizes the network stationinformation associated with the second base station to determine theposition of the mobile device. If the trustworthiness values of both thefirst and second base stations are equal, then the positiondetermination module 340 can be configured to use the network stationinformation for either or both in determining the position of the mobiledevice. In an example, the base station with the smaller MAR (MaximumAntenna Radius) can be sued to determine the location of the mobiledevice.

In operation, referring to FIG. 12, with further reference to FIG. 3, aprocess 1200 for sending network station information based on atrustworthiness value is shown. The process 1200, however, is exemplaryonly and not limiting. The process 1200 may be altered, e.g., by havingstages added, removed, or rearranged.

At stage 1202 the position determination module 340 can receive arequest for network station information that is associated with one ormore base stations. In this example, the term base station can be a WANbase station 312 or an access point 324. In general, the request for thenetwork information can originate from a mobile device 100, or fromwithin the position determination module 340. For example, a positiondetermining algorithm executing in the position determination module caninclude a function for retrieving network station information from thealmanacs 344 a, 344 b. At stage 1204, the position determination module340 can determine the trustworthiness value for each base station andcompare the trustworthiness values to a threshold value at stage 1206.The threshold value can be one or more predetermined values stored inthe memory of the position determination module (e.g., a look-up table).As an example, and not a limitation, the threshold value can correspondto other system parameters such as type of mobile device, time of day,and the number of base stations in the request. At stage 1208, theposition determination module 340 can be configured to determine if thetrustworthiness values for each of the request base stations meets orexceeds the threshold value. That is, the position determination module340 will send only the trustworthy network station information (i.e.,those which meet an established threshold) at stage 1210, or evaluateanother requested base station at stage 1212. The trustworthy networkinformation can be sent serially or in a batch.

As an example of operation, the mobile device 100 can detect ofplurality of MAC addresses and/or BSIDs for a plurality of basestations. The mobile device 100 can send these addresses to the positiondetermination module 340 via one or more communication links 123, 132.The position determination module 340 can execute an API call includingthe MAC, BSID or other identifying information to the almanac processor322. In an embodiment, the API call can be a SQL stored procedure thatis stored on the almanac processor 322. In general, this storedprocedure executes a select query on one or more of the almanacs 344 a,344 b based on the identifying information. The query can also include athreshold value as either a fixed parameter in the query, or as avariable within the API call. This threshold value may be used to filterthe results of the select query. When the query is executed, the almanacprocessor 322 returns the network station information associated withidentifying information if the network station information istrustworthy (i.e., meets or exceeds the threshold value). Thetrustworthy network station information can be sent to the positiondetermination module 340 and/or the mobile device 100 to be used by aposition determination algorithm.

As used herein, including in the claims, “or” as used in a list of itemsprefaced by “at least one of” indicates a disjunctive list such that,for example, a list of “at least one of A, B, or C” means A or B or C orAB or AC or BC or ABC (i.e., A and B and C), or combinations with morethan one feature (e.g., AA, AAB, ABBC, etc.).

Other examples and implementations are within the scope and spirit ofthe disclosure and appended claims. For example, due to the nature ofsoftware, functions described above can be implemented using softwareexecuted by a processor, hardware, firmware, hardwiring, or combinationsof any of these. Features implementing functions may also be physicallylocated at various positions, including being distributed such thatportions of functions are implemented at different physical locations.For example, position determination algorithms can be executed withinthe position determination module 340, or within the mobile device 100.

Substantial variations to described configurations may be made inaccordance with specific requirements. For example, customized hardwaremight also be used, and/or particular elements might be implemented inhardware, software (including portable software, such as applets, etc.),or both. Further, connection to other computing devices such as networkinput/output devices may be employed.

Common forms of physical and/or tangible computer-readable mediainclude, for example, a floppy disk, a flexible disk, hard disk,magnetic tape, or any other magnetic medium, a CD-ROM, any other opticalmedium, punchcards, papertape, any other physical medium with patternsof holes, a RAM, a PROM, EPROM, a FLASH-EPROM, any other memory chip orcartridge, a carrier wave as described hereinafter, or any other mediumfrom which a computer can read instructions and/or code.

The methods, systems, and devices discussed above are examples. Variousconfigurations may omit, substitute, or add various procedures orcomponents as appropriate. For instance, in alternative configurations,the methods may be performed in an order different from that described,and that various steps may be added, omitted, or combined. Also,features described with respect to certain configurations may becombined in various other configurations. Different aspects and elementsof the configurations may be combined in a similar manner. Also,technology evolves and, thus, many of the elements are examples and donot limit the scope of the disclosure or claims.

Specific details are given in the description to provide a thoroughunderstanding of example configurations (including implementations).However, configurations may be practiced without these specific details.For example, well-known circuits, processes, algorithms, structures, andtechniques have been shown without unnecessary detail in order to avoidobscuring the configurations. This description provides exampleconfigurations only, and does not limit the scope, applicability, orconfigurations of the claims. Rather, the preceding description of theconfigurations provides a description for implementing describedtechniques. Various changes may be made in the function and arrangementof elements without departing from the spirit or scope of thedisclosure.

Also, configurations may be described as a process which is depicted asa flow diagram or block diagram. Although each may describe theoperations as a sequential process, many of the operations can beperformed in parallel or concurrently. In addition, the order of theoperations may be rearranged. A process may have additional stages orfunctions not included in the figure. Furthermore, examples of themethods may be implemented by hardware, software, firmware, middleware,microcode, hardware description languages, or any combination thereof.When implemented in software, firmware, middleware, or microcode, theprogram code or code segments to perform the tasks may be stored in anon-transitory computer-readable medium such as a storage medium.Processors may perform the described tasks.

Having described several example configurations, various modifications,alternative constructions, and equivalents may be used without departingfrom the spirit of the disclosure. For example, the above elements maybe components of a larger system, wherein other rules may takeprecedence over or otherwise modify the application of the invention.Also, a number of operations may be undertaken before, during, or afterthe above elements are considered. Accordingly, the above descriptiondoes not bound the scope of the claims.

Position determination and estimation techniques described herein may beimplemented in conjunction with various wireless communication networkssuch as a wireless wide area network (WWAN), a wireless local areanetwork (WLAN), a wireless personal area network (WPAN), and so on. Theterm “network” and “system” are often used interchangeably. A WWAN maybe a Code Division Multiple Access (CDMA) network, a Time DivisionMultiple Access (TDMA) network, a Frequency Division Multiple Access(FDMA) network, an Orthogonal Frequency Division Multiple Access (OFDMA)network, a Single-Carrier Frequency Division Multiple Access (SC-FDMA)network, a Long Term Evolution (LTE) network, a WiMAX (IEEE 802.16)network and so on. A CDMA network may implement one or more radio accesstechnologies (RATs) such as cdma2000, Wideband-CDMA (W-CDMA), and so on.Cdma2000 includes IS-95, IS-2000, and IS-856 standards. A TDMA networkmay implement Global System for Mobile Communications (GSM), DigitalAdvanced Mobile Phone System (D-AMPS), or some other RAT. GSM and W-CDMAare described in documents from a consortium named “3rd GenerationPartnership Project” (3GPP). Cdma2000 is described in documents from aconsortium named “3rd Generation Partnership Project 2” (3GPP2). 3GPPand 3GPP2 documents are publicly available. A WLAN may be an IEEE802.11x network, and a WPAN may be a Bluetooth network, an IEEE 802.15x,or some other type of network. The techniques may also be implemented inconjunction with any combination of WWAN, WLAN and/or WPAN.

The methodologies described herein may be implemented by various meansdepending upon the application. For example, these methodologies may beimplemented in hardware, firmware, software, or any combination thereof.For an implementation involving hardware, the processing units may beimplemented within one or more application specific integrated circuits(ASICs), digital signal processors (DSPs), digital signal processingdevices (DSPDs), programmable logic devices (PLDs), field programmablegate arrays (FPGAs), processors, controllers, micro-controllers,microprocessors, electronic devices, other electronic units designed toperform the functions described herein, or a combination thereof.

For an implementation involving firmware and/or software, themethodologies may be implemented with modules (e.g., procedures,functions, and so on) that perform the functions described herein. Anymachine-readable medium tangibly embodying instructions may be used inimplementing the methodologies described herein. For example, softwarecodes may be stored in a memory and executed by a processing unit.Memory may be implemented within the processing unit or external to theprocessing unit. As used herein the term “memory” refers to any type oflong term, short term, volatile, nonvolatile, or other memory and is notto be limited to any particular type of memory or number of memories, ortype of media upon which memory is stored.

If implemented in firmware and/or software, the functions may be storedas one or more instructions or code on a computer-readable medium.Examples include computer-readable media encoded with a data structureand computer-readable media encoded with a computer program.Computer-readable media includes physical computer storage media. Astorage medium may be any available medium that can be accessed by acomputer. By way of example, and not limitation, such computer-readablemedia can comprise RAM, ROM, EEPROM, CD-ROM or other optical diskstorage, magnetic disk storage, semiconductor storage, or other storagedevices, or any other medium that can be used to store desired programcode in the form of instructions or data structures and that can beaccessed by a computer; disk and disc, as used herein, includes compactdisc (CD), laser disc, optical disc, digital versatile disc (DVD),floppy disk and Blu-ray disc where disks usually reproduce datamagnetically, while discs reproduce data optically with lasers.Combinations of the above should also be included within the scope ofcomputer-readable media.

What is claimed is:
 1. A method of using a mobile device to transfertrust between networks, comprising: receiving a WAN base stationinformation including a WAN base station trustworthiness value;determining a WAN position estimate for the mobile device based on theWAN base station information; receiving an access point informationincluding an access point trustworthiness value; determining an accesspoint position estimate for the mobile device based on the access pointinformation; determining if the WAN position estimate and the accesspoint position estimate are corroborated; and increasing the accesspoint trustworthiness value if the WAN position estimate and the accesspoint position estimate are corroborated and the WAN base stationtrustworthiness value is higher than the access point trustworthinessvalue.
 2. The method of claim 1, comprising increasing the WAN basestation trustworthiness value if the WAN position estimate and theaccess point position estimate are corroborated and the access pointtrustworthiness value is higher than the WAN base stationtrustworthiness value.
 3. The method of claim 1, comprising: determininga combined position estimate based on the WAN base station informationand the access point information; and outputting the combined positionestimate.
 4. The method of claim 1, comprising: disregarding the accesspoint position estimate if the WAN position estimate and the accesspoint position estimate are uncorroborated and the WAN base stationtrustworthiness value is higher than the access point trustworthinessvalue; and outputting the WAN position estimate.
 5. The method of claim4, comprising decreasing the access point trustworthiness value.
 6. Themethod of claim 1, comprising: disregarding the WAN position estimate ifthe WAN position estimate and the access point position estimate areuncorroborated and the WAN base station trustworthiness value is lowerthan the access point trustworthiness value; and outputting the accesspoint position estimate.
 7. The method of claim 6, comprising decreasingthe WAN base station trustworthiness value.
 8. A system for transferringtrust between network base stations, comprising: a base station databaseoperative to maintain a database identifying a plurality of WAN basestations and corresponding WAN location information, and a plurality ofaccess points and corresponding access point location information,wherein the WAN location information includes a WAN trustworthinessvalue for each of the plurality of WAN base stations, and the accesspoint location information includes an access point trustworthinessvalue for each of the plurality of access points; a positiondetermination module configured to: determine a WAN position estimatefor a mobile device based on the WAN location information correspondingto a WAN base station that is in communication with the mobile device;determine an access point position estimate for the mobile device basedon the access point location information corresponding to an accesspoint that is in communication with the mobile device; an almanacprocessor configured to: compare the WAN trustworthiness valueassociated with the WAN base station and the access pointtrustworthiness value associated with the access point; determine if theWAN position estimate and the access point position estimate arecorroborated; increase the access point trustworthiness value if the WANposition estimate and the access point position estimate arecorroborated and the WAN trustworthiness value higher than the accesspoint trustworthiness value; and increase the WAN trustworthiness valueif the WAN position estimate and the access point position estimate arecorroborated and the WAN trustworthiness value is lower than the accesspoint trustworthiness value.
 9. The system of claim 8, wherein theposition determination module is configured to determine a combinedposition estimate based on the WAN position estimate and the accesspoint position estimate.
 10. The system of claim 8, wherein the positiondetermination module is configured to: disregard the access pointposition estimate if the WAN position estimate and the access pointposition estimate are uncorroborated and the WAN trustworthiness valueis higher than the access point trustworthiness value; and output theWAN position estimate.
 11. The system of claim 10, wherein the almanacprocessor is configured to decrease the access point trustworthinessvalue.
 12. The system of claim 8, wherein the position determinationmodule is configured to: disregard the WAN position estimate if the WANposition estimate and the access point position estimate areuncorroborated and the access point trustworthiness value is higher thanthe WAN trustworthiness value; and output the access point positionestimate.
 13. The system of claim 12, wherein the almanac processor isconfigured to decrease the WAN trustworthiness value.
 14. The system ofclaim 8, wherein the position determination module is configured todetermine the access point position estimate of the mobile device basedon location information corresponding to a plurality of access pointsthat are in communication with the mobile device.
 15. The system ofclaim 8, wherein the position determination module is configured todetermine the WAN position estimate of the mobile device based onlocation information corresponding to a plurality WAN base stations thatare in communication with the mobile device.
 16. An apparatus fortransferring trust between networks, comprising: means for receiving aWAN base station information including a WAN base stationtrustworthiness value; means for determining a WAN position estimate fora mobile device based on the WAN base station information; means forreceiving an access point information including an access pointtrustworthiness value; means for determining an access point positionestimate for the mobile device based on the access point information;means for determining if the WAN position estimate and the access pointposition estimate are corroborated; and means for increasing the accesspoint trustworthiness value if the WAN position estimate and the accesspoint position estimate are corroborated and the WAN base stationtrustworthiness value is higher than the access point trustworthinessvalue.
 17. The method of claim 16, comprising means for increasing theWAN base station trustworthiness value if the WAN position estimate andthe access point position estimate are corroborated and the access pointtrustworthiness value is higher than the WAN base stationtrustworthiness value.
 18. The method of claim 16, comprising: means fordetermining a combined position estimate based on the WAN base stationinformation and the access point information; and means for outputtingthe combined position estimate.
 19. The method of claim 16, comprising:means for disregarding the access point position estimate if the WANposition estimate and the access point position estimate areuncorroborated and the WAN base station trustworthiness value is higherthan the access point trustworthiness value; and means for outputtingthe WAN position estimate.
 20. The method of claim 19, comprising meansfor decreasing the access point trustworthiness value.
 21. The method ofclaim 16, comprising: means for disregarding the WAN position estimateif the WAN position estimate and the access point position estimate areuncorroborated and the WAN base station trustworthiness value is lowerthan the access point trustworthiness value; and means for outputtingthe access point position estimate.
 22. The method of claim 21,comprising decreasing the WAN base station trustworthiness value.
 23. Acomputer program product residing on a processor-executable computerstorage medium, the computer program product comprisingprocessor-executable instructions configured to cause a processor to:receive WAN base station information including a WAN base stationtrustworthiness value; determine a WAN position estimate for a mobiledevice based on the WAN base station information; receive an accesspoint information including an access point trustworthiness value;determine an access point position estimate for the mobile device basedon the access point information; determine if the WAN position estimateand the access point position estimate are corroborated; and increasethe access point trustworthiness value if the WAN position estimate andthe access point position estimate are corroborated and the WAN basestation trustworthiness value is higher than the access pointtrustworthiness value.
 24. The computer program product of claim 23,further comprising instructions configured to cause the processor toincrease the WAN base station trustworthiness value if the WAN positionestimate and the access point position estimate are corroborated and theaccess point trustworthiness value is higher than the WAN base stationtrustworthiness value.
 25. The computer program product of claim 23,further comprising instructions configured to cause the processor to:determine a combined position estimate based on the WAN base stationinformation and the access point information; and output the combinedposition estimate.
 26. The computer program product of claim 23, furthercomprising instructions configured to cause the processor to: disregardthe access point position estimate if the WAN position estimate and theaccess point position estimate are uncorroborated and the WAN basestation trustworthiness value is higher than the access pointtrustworthiness value; and output the WAN position estimate.
 27. Thecomputer program product of claim 26, further comprising instructionsconfigured to cause the processor to decrease the access pointtrustworthiness value.
 28. The computer program product of claim 23,further comprising instructions configured to cause the processor to:disregard the WAN position estimate if the WAN position estimate and theaccess point position estimate are uncorroborated and the WAN basestation trustworthiness value is lower than the access pointtrustworthiness value; and output the access point position estimate.29. The computer program product of claim 28, further comprisinginstructions configured to cause the processor to decrease the WAN basestation trustworthiness value.
 30. A method of using a mobile device totransfer trust between networks, comprising: receiving a plurality offirst network station information from a plurality of base stations;determining a first position estimate for the mobile device based on theplurality of first network station information; receiving a secondnetwork station information from a single base station, wherein thesingle base station is not one of the plurality of base stations;determining a location of the single base station; determining if thefirst position estimate for the mobile device and the location of thesingle base station are corroborated; and increasing a trustworthinessvalue associated with the single base station if the first positionestimate for the mobile device and the location of the single basestation are corroborated.
 31. The method of claim 30, comprisingdetermining a second position estimate for the mobile device based onthe plurality of first network station information received from theplurality of base stations and the second network station informationreceived from the single base station.
 32. The method of claim 30,comprising decreasing the trustworthiness value associated with thesingle base station if the first position estimate for the mobile deviceand the location of the single base station are uncorroborated.
 33. Anapparatus for transferring trust between networks, comprising: means forreceiving a plurality of first network station information from aplurality of base stations; means for determining a first positionestimate for a mobile device based on the plurality of first networkstation information; means for receiving a second network stationinformation from a single base station, wherein the single base stationis not one of the plurality of base stations; means for determining alocation of the single base station; means for determining if the firstposition estimate for the mobile device and the location of the singlebase station are corroborated; and means for increasing atrustworthiness value associated with the single base station if thefirst position estimate for the mobile device and the location of thesingle base station are corroborated.
 34. The apparatus of claim 33,comprising means for determining a second position estimate for themobile device based on the plurality of first network stationinformation received from the plurality of base stations and the secondnetwork station information received from the single base station. 35.The apparatus of claim 33, comprising means for decreasing thetrustworthiness value associated with the single base station if thefirst position estimate for the mobile device and the location of thesingle base station are uncorroborated.
 36. An apparatus for transfertrust between networks, comprising: a memory; a processor configured to:receive a plurality of first network station information from aplurality of base stations; determine a first position estimate for amobile device based on the plurality of first network stationinformation; receive a second network station information from a singlebase station, wherein the single base station is not one of theplurality of base stations; determine a location of the single basestation; determine if the first position estimate for the mobile deviceand the location of the single base station are corroborated; andincrease a trustworthiness value associated with the single base stationif the first position estimate for the mobile device and the location ofthe single base station are corroborated, wherein the trustworthinessvalue is stored in the memory.
 37. The apparatus of claim 36, whereinthe processor is configured to determine a second position estimate forthe mobile device based on the plurality of first network stationinformation received from the plurality of base stations and the secondnetwork station information received from the single base station. 38.The apparatus of claim 36, wherein the processor is configured todecrease the trustworthiness value associated with the single basestation if the first position estimate for the mobile device and thelocation of the single base station are uncorroborated.
 39. A computerprogram product residing on a processor-executable storage medium, thecomputer program product comprising processor-executable instructionsconfigured to cause a processor to: receive a plurality of first networkstation information from a plurality of base stations; determine a firstposition estimate for a mobile device based on the plurality of firstnetwork station information; receive a second network stationinformation from a single base station, wherein the single base stationis not one of the plurality of base stations; determine a location ofthe single base station; determine if the first position estimate forthe mobile device and the location of the single base station arecorroborated; and increase a trustworthiness value associated with thesingle base station if the first position estimate for the mobile deviceand the location of the single base station are corroborated.
 40. Thecomputer program product of claim 39, comprising instructions configuredto cause the processor to determine a second position estimate for themobile device based on the plurality of first network stationinformation received from the plurality of base stations and the secondnetwork station information received from the single base station. 41.The computer program product of claim 39, comprising instructionsconfigured to cause the processor to decrease the trustworthiness valueassociated with the single base station if the first position estimatefor the mobile device and the location of the single base station areuncorroborated.
 42. A method of determining a position of a mobiledevice, comprising: receiving a first network station information from afirst base station, including a first location information and a firsttrustworthiness value for the first base station; receiving a secondnetwork station information from a second base station, including asecond location information and a second trustworthiness value for thesecond base station; determining if the first location information andthe second location information corroborate with one another;determining a first position estimate for the mobile device based on thefirst network station information and the second network stationinformation if the first location information and the second locationinformation are corroborated; determining a second position estimate forthe mobile device based on the first network station information if thefirst location information and the second location information areuncorroborated and the first trustworthiness value is higher than thesecond trustworthiness value; and determining a third position estimatefor the mobile device based on the second network station information ifthe first location information and the second location information areuncorroborated and the second trustworthiness value is higher than thefirst trustworthiness value.
 43. An apparatus for determining a positionof a mobile device, comprising: means for receiving a first networkstation information from a first base station, including a firstlocation information and a first trustworthiness value for the firstbase station; means for receiving a second network station informationfrom a second base station, including a second location information anda second trustworthiness value for the second base station; means fordetermining if the first location information and the second locationinformation corroborate with one another; means for determining a firstposition estimate for the mobile device based on the first networkstation information and the second network station information if thefirst location information and the second location information arecorroborated; means for determining a second position estimate for themobile device based on the first network station information if thefirst location information and the second location information areuncorroborated and the first trustworthiness value is higher than thesecond trustworthiness value; and means for determining a third positionestimate for the mobile device based on the second network stationinformation if the first location information and the second locationinformation are uncorroborated and the second trustworthiness value ishigher than the first trustworthiness value.
 44. An apparatus fordetermining a position of a mobile device, comprising: a memory; aprocessor coupled to the memory and configured to: receive a firstnetwork station information from a first base station, including a firstlocation information and a first trustworthiness value for the firstbase station; receive a second network station information from a secondbase station, including a second location information and a secondtrustworthiness value for the second base station; determine if thefirst location information and the second location informationcorroborate with one another; determine a first position estimate forthe mobile device based on the first network station information and thesecond network station information if the first location information andthe second location information are corroborated; determine a secondposition estimate for the mobile device based on the first networkstation information if the first location information and the secondlocation information are uncorroborated and the first trustworthinessvalue is higher than the second trustworthiness value; determine a thirdposition estimate for the mobile device based on the second networkstation information if the first location information and the secondlocation information are uncorroborated and the second trustworthinessvalue is higher than the first trustworthiness value; and store a mobiledevice position in the memory, wherein the position is selected from agroup consisting of the first, second, and third position estimates. 45.A computer program product residing on a processor-executable computerstorage medium, the computer program product comprisingprocessor-executable instructions configured to cause a processor to:receive a first network station information from a first base station,including a first location information and a first trustworthiness valuefor the first base station; receive a second network station informationfrom a second base station, including a second location information anda second trustworthiness value for the second base station; determine ifthe first location information and the second location informationcorroborate with one another; determine a first position estimate for amobile device based on the first network station information and thesecond network station information if the first location information andthe second location information are corroborated; determine a secondposition estimate for the mobile device based on the first networkstation information if the first location information and the secondlocation information are uncorroborated and the first trustworthinessvalue is higher than the second trustworthiness value; and determine athird position estimate for the mobile device based on the secondnetwork station information if the first location information and thesecond location information are uncorroborated and the secondtrustworthiness value is higher than the first trustworthiness value.46. A method of determining a position of a mobile device, comprising:receiving a request for a network station information associated withone or more base stations, wherein the network station informationincludes a trustworthiness value for each base station; comparing thetrustworthiness value for each base station to a threshold value;utilizing the network station information for the one or more basestations that have a trustworthiness value equal to or greater than thethreshold value to calculate a position for the mobile device; andoutputting the position of the mobile device.
 47. An apparatus fordetermining a position of a mobile device, comprising: means forreceiving a request for a network station information associated withone or more base stations, wherein the network station informationincludes a trustworthiness value for each base station; means forcomparing the trustworthiness value for each base station to a thresholdvalue; means for utilizing the network station information for the oneor more base stations that have a trustworthiness value equal to orgreater than the threshold value to calculate a position for the mobiledevice; and means for outputting the position of the mobile device. 48.An apparatus for determining a position of a mobile device, comprising:a memory; a processor configured to: receive a request for a networkstation information associated with one or more base stations, whereinthe network station information is stored in the memory and includes atrustworthiness value for each base station; compare the trustworthinessvalue for each base station to a threshold value; utilize the networkstation information for the one or more base stations that have atrustworthiness value equal to or greater than the threshold value tocalculate a position for the mobile device; and output the position ofthe mobile device.
 49. A computer program product residing on aprocessor-executable computer storage medium, the computer programproduct comprising processor-executable instructions configured to causea processor to: receive a request for a network station informationassociated with one or more base stations, wherein the network stationinformation includes a trustworthiness value for each base station;compare the trustworthiness value for each base station to a thresholdvalue; utilize the network station information for the one or more basestations that have a trustworthiness value equal to or greater than thethreshold value to calculate a position for a mobile device; and outputthe position of the mobile device.